Are you aware that advertising is explicitly defined in law, and already regulated, even in the USA?
In fact, the definition is extremely simple: if a company payed you (with money, free product, free trips etc) to say or show something about their product, that is advertising, regardless of what you are saying or of whether you believe it. No more, no less.
Note: some countries extend this to any display or mention of branding, whether payed for or not, at least in broadcast media. So, for example in my country, a TV show has to blur out brands on bottles of water or cars shown, or display an explicit "this is advertising" logo on the screen while the branding is shown.
In fact, the definition is extremely simple: if a company payed you (with money, free product, free trips etc) to say or show something about their product, that is advertising, regardless of what you are saying or of whether you believe it. No more, no less.
Note: some countries extend this to any display or mention of branding, whether payed for or not, at least in broadcast media. So, for example in my country, a TV show has to blur out brands on bottles of water or cars shown, or display an explicit "this is advertising" logo on the screen while the branding is shown.